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Medicines, eggs, and embryos · Topic 15 of 40

Why did some eggs not fertilize?

Not every retrieved egg is mature. Not every mature egg fertilizes after sperm is added or injected.

What you should know

Fertilization depends on the egg, sperm, and lab process. Some eggs show abnormal fertilization. Your lab can explain how many eggs were mature and how many fertilized in the expected way. One cycle may not explain why a problem happened.

What to ask your care team

“How many mature eggs did I have, and what does fertilization tell us?”

One important reminder

A low fertilization number does not by itself prove the cause.

Before your next visit

Write down your questions. Bring your medicine list and any test results you have. Ask for a plan in writing. If an answer is not clear, ask your team to explain it in a different way.

More trusted information

These sources offer more detail. They do not replace advice from your fertility clinic.